1. Technical Field
The present disclosure relates to an exhaust gas control system for an internal combustion engine.
2. Description of Related Art
A system known as an exhaust gas control system for an internal combustion engine includes: an oxidation catalyst disposed in an exhaust passage of the internal combustion engine; a selective catalytic; reduction (SCR) catalyst disposed in a portion of the exhaust passage downstream from the oxidation catalyst; a fuel addition valve disposed in a portion of the exhaust passage upstream from the oxidation catalyst, the fuel addition valve being configured to add fuel to the exhaust gas; and a urea addition valve disposed in a portion of the exhaust passage between the fuel addition valve and the SCR catalyst, the urea addition valve being configured to add a urea aqueous solution to the exhaust gas (see, for example, Japanese Patent Application Publication No. 2012-097729).